The Moon Society Forum

March 6, 2009
We incubated radish plants in a plant chamber under 24/7 lighting.

We wanted to see haw the radishes adapted to the poor soil conditions of Groveland iron mine tailings. We found that in pure mine tailing that the radishes would sprout but then die suddenly after two weeks. I theory was that the nutrition from the original seed was exhausted on the one hand and the iron tailngs were nutrient poor on the other, even if the temperature and water supply were adequate. Third the root systems did not develop in the mine tailing to the same extent that control plants did in regular potting soil. The root systems that developed in the ion tailings were 1/4 the size of those that developed in the potting soil and the young plants fell over from lack of root support. The density of the iron tailings we hypothesized limited the ability of the roots to penetrate the material.

We began to vary the composition between mine tailing and small pebble ranging from 90/10 tailings/pebbles to
80/ pebbles 10% tailings and 10% potting soil on the theory that that the voids and irregular surface of the pebbles would create more voids for the penetration of the roots. On the 80/10/10 mixture the radish plants seemed to survive after two weeks.

We then added another half cup of pyrogenic carbon material to the 80/10/10 formula and tried again. This time
we experienced much better development. The addition of the pyrogenic carbon seemed to really increase the vigor of the plant growth in what would still have to be described as sub-prime soils. The clay pots were placed in a surrounding plastic bowl which was filled with water qnd which provided a continous water supply during the
trial. As of March 14 we have not looked at the root systems to determine the extent of the root systems.
These plants have out performed a control group that was in only potting soil. but this result is not validated by many trails and is based on the results of just one pot. We are trying to see how very poor beginning soil materials can be colonized by plants and then evolve into more organically enriched soils over a few generations


We will repeat this experiment comparing the plant growth of radishes in 10% JSC#1, with 70% pebbles, 10%
potting soil, and pyrogenic carbon. compared with 10% Groveland mine tailings, with 10% potting soil component and 10% pyrogenic carbon mixture along with continous bottom water supply. Our interest is to see how effectively these plants can grow in a very rocky 70% pebble substrate with 10% fine rock particles, 10% potting soils, and 10% pyrogenic carbon.

This is to test how plants might colonize poor soils then grow and with successive generations improved the soils if these plants are "tilled under" to increase the organic content of the pot over a period of 10 generations or approximately a year.

Note we understand that initially hydroponic systems will provide much more efficiently for optimum food production and for the operation of bio-regeneraive life support systems. These experiments however look forward to establishing a more Earth like process of soil based horticulture and the production of soils which
can be utilized by a wide spectrum of diversified plants from in situ materials. This is an issue which cannot ultimately be avoided if we are to establish off Earth biospheres which is representative of the wide diversity of soil based plants and associated organisms.

Dave Dunlop


We were curious to see